Discuss the different evidences of evolution

1. EVOLUTION
Is a genetic change in a
population through time
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3. Charles Darwin
On his journey around the
world, He found evidence
of gradual
change(evolution).
He cited evidences he
found in fossil records,
geographic distribution
and homologous
structures. 3

4. Evidence of Evolution
Today most evidences are grouped into
five main categories:
Fossils
Geographical Distribution
Embryology
Comparative Anatomy
Molecular and Genetic
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5. Evidence
Evidence of
common
ancestry
among species
comes from
many sources.
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6. #1 Fossil Evidence
 Fossils
o Earth is Millions of
years old!
o Fossils in older layers
are more primitive than
those in the upper
layers.
o Extinct Fossils resemble
modern animals.
o This shows a common
ancestry.
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8. #2 Geographical Distribution
 Geography & environment gives
evidence for evolution
 Island species most closely resemble
nearest mainland species
 Populations can show variation from
one island to another
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9. #2 Geographical Distribution
• The geographical distribution of species can
help us reconstruct their evolutionary
histories
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Marsupial
mammals Australia are marsupials (carry
young in a pouch).
Most mammal species
elsewhere in the world are
placental (nourish young
through a placenta).

10. #3 Embryology
 Embryo (early developmental stage) gives
evidence of evolution
 Identical larvae, different adult body
forms
 Similar embryos, related but diverse
organisms
 Shows
common
ancestry
Larva
Adult barnacle
Adult crab
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12. #3 Embryology
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Vertebrates
all share gill
slits and a
tail in their
early
embryo
stage;
Share a
common
ancestor

13. #4 Comparative Anatomy
 The study of anatomy provides
evidence of evolution
 Homologous structures are
similar in structure but
different in function.
 Homologous structures ARE
EVIDENCE of a common
ancestor.
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14. Homologous Structures
ARM LEG Flipper Wing
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15. #4 Comparative Anatomy
 Analogous structures are similar
in function but differ in structure
 Analogous structures DO NOT
show common ancestry
Fly wing
Bat wing 15

16. Structural patterns are clues
to the history of a species.
Vestigial structures are remnants of
organs or structures that had a
function in an early ancestor.
Examples include ostrich wings, human
appendix, and wisdom teeth, whale
and snake pelvis/hind legs
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17. Pythons have tiny
femurs (leg bone)
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18. #5 Molecular and Genetic
Evidence
 AKA Biochemical
Evidence
 Two closely-related
organisms will have
similar DNA, RNA, and
protein (amino acid)
sequences.
 This also gives
evidence of a common
ancestor. 18

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More closely related organisms will have more similar cyt c because
they have more recent common ancestor. The more recent the
common ancestor, the less time for DNA mutations to occur. Changes
in DNA lead to changes in mRNA leads to differences in protein
amino acid sequences.

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22. Five examples of Evidence
for Evolution
1.Fossils
2.Geographical Distribution
3.Embryology
4.Comparative Anatomy
5.Molecular and Genetic
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23. Post-activity
1. Explain how fossil records, comparative
anatomy, and genetic information prove
evolution.
2. Compare homologous, analogous, and
vestigial structures.
3. Identify the effect of gene mutation on the
evolution of the species
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